The right click doesn't actually scale the blocks, it's the scroll wheel, and you have to hold left click otherwise you just shoot the blocks. Be careful on the 4th level, if you accidently glitch the block through the floor you have to restart the game because there's only one block to start. I had to restart twice but the first couple levels are pretty easy so it wasn't too annoying.
Overall it's a very unique concept and a really fun game. It may sound like I only have bad things to say, but I just wanted to make a couple notes so that it's easier for future players.